(1½" to 3" Drain & Sewer Lines)

You're on a service call; a slow 2-inch drain line that's backing up, probably grease. You've got a jetter on the jobsite and you're ready to get to work. But before you ever decide which nozzle is best to attack the blockage, you first need to answer a more important question:

Do you have the right jetting hose for the job?

This is a common mistake. Operators often spend a lot of time thinking about nozzles, yet the jetting hose you choose determines how much of your jetter's GPM and PSI actually makes it to the nozzle, and how easily you'll navigate – or fail to navigate – bends and P-traps in the line. Choosing the right hose size and type for the particular drainline is primary, because the nozzle-selection will be limited to those that’ll thread onto the hose’s end..

To get the best results in smaller drain lines, you need to make two decisions:

1. First choose the right hose size and type for the pipe you want to clean.

2. Then choose the right nozzle type for the job at hand.

This first of two blogs will focus on the hose side of that equation. In Part 2, we'll cover choosing the right nozzle types for grease, hard stoppages, P-traps, maintenance flushing, and more. (Part 2 Coming Soon)

Why Small-Diameter Lines Require a Different Approach

Small-diameter pipe cleaning isn't just scaled-down jetting. Many operators make the mistake of treating 1.5 and 2-inch lines like a smaller version of a 4-inch jetting job. Same jetter, same hose, just push it in and let it run. That approach works until it doesn't, and in a small-diameter pipe it can stop working fast, often stalling at the first bend. The pipe geometry, the flow dynamics, and the hose/nozzle combination all interact differently when the pipe's bore gets tighter. Small-diameter pipe cleaning is its own discipline.

Hose Stiffness Matters More in Small Lines

In a 4-inch line, hose stiffness is a minor inconvenience, but in a 1.5-inch, 2-inch, or even a 3-inch line, a hose that is too stiff -- or too floppy -- can stall a job completely.

When the pipe is small, a stiff hose can't make the bends it needs to. Hose-diameter selection matters here too; a mini-hose is more flexible, making it easier to navigate through smaller pipes with bends. There are multiple mini-hose sizes to choose from; see below for help in selecting the hose diameter that's most appropriate for the pipe you're entering.

Step 1: Choose the Right Hose (Before Choosing a Nozzle)

When setting up to jet a small-diameter pipe, hose selection comes first. Choosing the right hose size and type to actually get through the pipe, and around its bends, determines which nozzles are even on the table. We’ll get to nozzles in the next blog; let’s first talk “mini-hoses”:

Match the Mini-Hose to the Pipe Size to be Cleaned

Generally speaking, the smaller the pipe, the smaller and more flexible the hose needs to be, but there are exceptions.

1/8-inch Jetting Hose

For 1.5-inch lines and smaller, 1/8-inch mini-jetter hose is the most flexible option, but its tiny inside-diameter makes it extremely restrictive to your jetter's GPM-flow, causing severe pressure-drop (aka "friction loss") that can cut the GPM/PSI power from your jetter in half, or worse, before the water even gets to the nozzle. Also, 1/8-inch hose is extremely floppy and can coil up rather than pass through a bend or trap.

For these reasons, we generally do not recommend 1/8-inch hose for serious work. However, it is the least expensive because it is the smallest, making it suitable for homeowners and DIY types.

3/16-inch Jetting Hose

A better choice for pros jetting 1.5-inch lines and smaller is 3/16-inch jetting hose. Still very flexible, 3/16” jetting hoses actually have an 1/8-inch end-fitting to accommodate compact 1/8" nozzles.

The major benefit of 3/16” hose is more jetting-power to the nozzle, because the inside-diameter of 3/16-inch (.188-inch ID) hose is 50% larger than 1/8-inch (.125-inch ID). This makes 3/16-inch hose far less restrictive to your jetter's GPM/PSI output, allowing for significantly better cleaning power at the nozzle versus 1/8" hose.

What's more, premium 3/16-inch hose types have steel-braided reinforcement which makes the hose much more "pushable" to help get the hose and nozzle through tight bends and P-traps. Their unique combination of flexibility and pushability has earned these hose types the nickname "trap-jetting hose".

By contrast, “basic” 3/16-inch and 1/8-inch jetting hoses with polyester-braid reinforcement often ball up and stall when you try to push them through a P-trap or tight bend.

You can use 3/16-inch hose in 2-inch to 3-inch lines as well, especially if you are using an electric mini-jetter. And with larger jetters, 3/16” hose provides maximum flexibility and pushability to get the nozzle through a P-trap or tight bends.

1/4-inch and 5/16-inch Jetting Hoses

For larger gas-powered or diesel jetters, you can increase the GPM/PSI cleaning power at the nozzle by using a less restrictive 1/4-inch (.250-inch ID) or 5/16-inch (.312-inch ID) mini-hose.

The sweet spot for 1/4-inch hose is for jetters running 3 to 4 GPM. It is usable up to around 6 GPM, making it perfect for 2-inch lines and useful in 3-inch lines as well.

5/16-inch hose is the least restrictive of all mini-hoses, allowing 5 to 6 GPM jetting flow without significant pressure loss, and even handling up to 8 GPM. This makes 5/16” a great "step-down" hose size for larger trailer jetters and van-pack jetters. Usable in some 2-inch lines, most 3-inch lines, and any 4-inch line, 5/16-inch jetting hose is quite versatile.

PRO TIP: the higher GPM-capacity of 5/16-inch hose makes it usable with many premium grease-cutting nozzles and smaller root-cutting heads (provided your jetter has the GPM/PSI output to power the nozzle’s rotation).

Keep Mini-Hose Length to a Minimum 

The longer a hose is, the more pressure-drop (aka "friction loss") there is over its length, and this is especially noticeable with mini-hoses. For example, a 200-foot hose is twice as restrictive as a 100-foot hose. Unnecessarily long mini-hoses create excess pressure-drop, so if you'll primarily be using the mini-hose to jet short indoor branch lines, don't order a 150-foot or 200-foot hose. Order hose-lengths that match the majority of your work.

In fact, many operators keep a handy 25-foot trap-jetting hose for working floor drains, sinks, and P-traps. However, if you'll indeed need a longer hose for longer small-diameter drains, consider a 150-foot or 200-foot hose on a handy tote-reel, along with a 25-foot, 50-foot, or 75-foot hose for shorter runs.

You might consider choosing different lengths for different hose sizes, such as:

• 3/16-inch × 50 feet

• 1/4-inch × 150 feet, on a portable reel

• 5/16-inch × 200 feet, on a portable reel

There are many size and length options to choose from. It's all about having the right sizes for the lines you’ll jet.

PRO TIP: When using an Electric Mini-Jetter, hose-size choices are limited.  1/4-inch and 5/16-inch hoses are generally too large because small electric-powered jetters have very low flow-specs of 2-GPM or less. The extra weight of a larger hose -- plus the larger volume of water inside the larger hose -- is more difficult for the low GPM-output of a mini-jetter's nozzle to pull through the pipe, so stick with a 3/16-inch hose; it'll be easier for the nozzle to pull into the line and it'll move easier through bends and p-traps.

Choose the Right Hose, Then Select the Right Nozzle 

Once you've matched the mini-hose to the pipe at hand, you're set up to jet with confidence. Proper flexibility for better navigation through bends and traps while minimizing hose pressure-drop allows your jetter to feed a nozzle the GPM and PSI it needs to clean the pipe effectively.

Need help sizing a mini-hose for your rig, or picking the right one for the jobs you run most? Visit our online store to see the full mini-hose lineup, or give us a call and we'll help you dial in the right setup.

So, once the Mini-Hose is chosen for the smaller drain, the nozzle choice is next; check out Part 2 for choosing the right Nozzles to team with your Mini-Hoses. (Part 2 Coming Soon)

JETTERS NORTHWEST is a 20+ year-old product line of Seattle Pump & Equipment Co., a service and sales center for jetters for over 50 years.

Mini-Hose Frequently Asked Questions

Can I get more pressure at the nozzle if I use a smaller-diameter hose?
No, and this is a common misconception: A smaller-diameter hose increases restriction and pressure inside the hose itself which takes pressure away from the nozzle rather than empowering it. Too much “pressure drop” through the hose can also reduce the GPM reaching the nozzle by causing your jetter's pressure-relief valve to bleed off some water back to the pump's inlet -- reducing GPM-flow out of the nozzle. Your pressure-gauge might even show more PSI but the nozzle doesn’t see it, therefore switching to a smaller hose as an attempt to increase nozzle-pressure tends to make the actual jetting-power worse, not better. Further, adding hose pressure-drop may increase the jetter’s fuel-consumption or amp-load for zero benefit.

Won’t a Smaller Jetting Hose Choke Down the Flow from My Powerful Jetter?
Typically yes, and that can be part of the strategy. Indeed GPM clears buildup and PSI drives cutting action, but an overabundance of jetter GPM-flow in smaller lines can actually slow down the cleaning process. This is because the GPM-to-Pipe-Diameter ratio tightens dramatically when jetting smaller lines, and the jetter's water-flow will back up on itself if your jetter’s GPM is too high for the pipe size. This backing up muffles the water-jet action of the nozzle, which (a) significantly reduces cleaning efficiency and (b) can create a bigger mess if it causes the pipe to regurgitate back into the workspace.

Can I Get More GPM-Flow Out Of My Mini-Jetter if I Use a Larger Jetting Hose?
Only if your jetter’s hose is choking back GPM because it’s too small or too long to begin with (which is common with 1/8-inch hose). But if you are already getting full GPM out the nozzle as is, then a larger hose won't magically increase your mini-jetter's GPM output.  This is because Jetter pumps are “Positive-Displacement” (“PD”) which simply means the pump’s GPM does not increase or decrease due to changes in pressure, which is very different that common "centrifugal" pump-types (like a sprinkler pump, sump pump, etc.) that will gain GPM as pressure is lowered.  By contrast, PD pump-flow only changes when its motor/engine RPM changes, thus your jetter's full-throttle GPM is its maximum GPM; increasing hose-size won’t magically make your jetter’s pump put out more flow.